Indicating device



Feb. 5, 1957 v ELLIOTT 2,780,686

INDICATING DEVICE Filed Aug. 4, 1955 INVENTOR,

ATTORNEYS.

United States Patent 6 INDICATING DEVICE Taylor M. Elliott, Richmond,Va.

Application August 4, 1955, Serial No. 526,523

8 Claims. (Cl. 200--56) This invention relates to improved apparatus forrendering a signal in the event that a measured quantity equals orexceeds a selected value, and in particular to improved apparatus foractuating an alarm or other indicator device in response to a vehiclespeed equal to or in excess of a selected value.

As a result of the modern improvements in automobiles, vehicle speeds inexcess of the prescribed limits for streets and highways are readilyattainable. In many instances the operators of these vehiclesunknowingly exceed the established limits through inadvertency, whichmay in part be caused by the relatively smooth functioning of recentmodels and also a natural tendency to increase vehicle speed duringperiods of sustained driving. It may be readily appreciated thatexcessive speeds are not conducive to safe driving, and with the recentinnovation of radar controlled streets and highways the drivers of thesevehicles also subject themselves to police action for momentarilyexcessive speeds which would otherwise go unnoticed.

Accordingly, a principal object of this invention is to provide improvedapparatus which will enable the driver of a vehicle to ascertain readilyand with a minimum of distraction that he is equaling or exceeding aselected speed.

Another object of this invention is to improve the visual appearance andthe readability of speedometer dials incorporating a speed selectorscale in association with the usual speed scale.

Another object of this invention is to provide speed selectoradaptations suitable for use with conventional speedometers, includingmodern wide dial speedometers, and requiring a minimum of adaptivemodification of the speedometer and its components.

Another object of this invention is to provide a speedometer alarmattachment which is readily adjustable to any selected speed, reliablein operation, and which may be easily repaired in the event of defectiveoperation.

A preferred embodiment of this invention contemplates a conventionalspeedometer which is modified to receive the speed selector attachmentof this invention. In particular, a linear speed selector scale isimprinted on the face of the speed indicator dial in such a manner thatthe speedometer pointer passes over the selector scale at a markednumerical value which corresponds with the pointer indicator speed. Aselector pointer, associated with the linear selector scale, is linearlymoved by the manual rotary operation of an exposed knob which drives aconcealed cable. The knob enables the operator to position the selectorpointer at any desired value of speed at which an alarm or the like isto be actuated in the event the vehicle is driven at a value equal to orin excess of the selected speed.

The alarm is electrically actuated by a closed circuit which isestablished when the speedometer pointer touches a contact projectingfrom the selector pointer. A completed electrical circuit is therebyestablished ice through the metallic speedometer pointer to ground, agrounded battery, the alarm device, and the metallic cable back to thespeedometer pointer.

While devices employing two contacting pointers have been disclosed inthe prior art to actuate a speedometer alarm, the specific constructionshown herein which features a cable-driven selector pointer movable overa linear scale associated with a speed scale has not been contemplated.The advantages of this invention over the prior art structures accrue toa large extent as a result of the foregoing structural innovations.

In order that all of the features for attaining the objects of thisinvention may be readily understood, detailed reference is made hereinto the accompanying drawings wherein:

Figure 1 is a simplified plan view of a conventional speedometermodified to incorporate the speed selector of this invention,

Figure 2 is a sectional view taken along line 22 of Figure 1 and showingin sectional detail the speedometer construction of this invention,

Figure 3 is a simplified view showing the alarm actuat ing circuit whichis established by the selector attachment herein,

Figure 4 is a view showing the manner in which the selector knob iscoupled to the speedometer casing,

Figure 5 is a perspective view showing in detail the manner in which theselector cable is attached to the selector pointer, and

Figure 6 is a view showing an alternative pulley arrangement forsupporting the selector cable.

Referring now to the drawings and in particular to Figure l, speedometer16, which is modified in accordance with the speed selector features ofthis invention, is positioned at a vehicle dashboard in the conventionalmanner. The modifications to the speedometer structure required topractice the present invention do not necessitate a difierentpositioning of the speedometer with respect to the associated dashboardinstrumentation than that which would otherwise be desirable.

Speedometer 10 includes dial plate 11 which is formed, for example, witha conventional numerical circular scale upon which vehicle speed isindicated by a metallic speedometer pointer 12. A numerical linear scaleis positioned at the lowermost edge portion of dial plate 11. Theparticular positioning of the numerical markings of this scale aredetermined so that the rightmost edge of speedometer pointer 12 willtouch the metallic contact finger 27 (Figure 5) projecting rearwardlyfrom a metallic selector pointer 13.

The internal speedometer structure is enclosed within a protectivehousing 14, which may in some instances be integral with the automobiledashboard, and formed in whole or in part from a suitable metal. Thishousing includes a front face portion 15 which is fabricated of metalbut which may in some circumstances be constructed of opaque ortranslucent glass so that the cable mechanism and other component partsshown in broken line in Figure 1 cannot be seen by the operator.Transparent glass plate 16 is coupled to protective housing 14 byconventional attachment means so that the dial plate 11 and the upperterminal portions of speedometer and selector pointers 12 and 13 arereadily visible to the vehicle operator. Dial plate 11 is supported inpart by a backing plate member 17 which extends from the upper and loweredge wall portions of the speedometer housing, and speedometer pointer12 is pivotally mounted with respect to backing plate 17 by structurewhich is conventional in the art. Speedometer pointer 12 is elongatedand fabricated with a relatively bright finish, and selector pointer 13is wide and fabricated with a relatively dark finish. This selectionavoids confusion of hands.

Cable pulleys 18 and 19 are rotatably supported with respect to thefront face portion of housing 14. Pulley 18 carries metallic cable 20,and pulley 19 serves to drive the cable and the attached selectorpointer 13 in response to a manual rotating force applied to knob 21. Asis best shown in Figure 4, pulley 19 is rigidly coupled to knob 21 bymeans of shaft 22. Shaft 22 passes through bushing 29 positioned onfront face portion 15 and therefore the shaft is free to rotate inresponse to the driving force applied to knob 21. Pulley 19 isfabricated of an electric insulating material to prevent shorting cableto ground.

Other arrangements for preventing the shorting of cable 20 to groundare, of course, possible, such as, for example, the fabrication of shaft22 or bushing 29 of electrical insulating material. Pulley 18 isfabricated of metal so that brush 23 can establish an electricalconnection to selector pointer 13 from alarm 24. Pulley 18 must besuitably supported so that it will not be shorted to the environmentalstructure.

As is best shown in Figure 5, selector pointer 13 is coupled to cable 20by spot welding the upper cable leg at weld point 25 and loosely passingthe lower cable leg through U-bolts 26. This coupling arrangement ofselector pointer 13 to cable 20 enables the pointer to move linearly inresponse to the movement of the cable 20.

A metallic contact finger 27 is attached to the uppermost portion of therear face of selector pointer 13. In a preferred arrangement, thecontact finger 27 is fabricated of spring metal so that speedometerpointer 12 can be driven past contact finger 27 thereby avoiding theapplication of harmful restraining forces to the speedometer cable andthe speedometer pointer. It will be understood, however, that an initialelectrical contact will nonetheless be established between thespeedometer pointer 12 and contact finger 27, this contact closure beingsuflicient to actuate the alarm momentarily.

As is best shown in Figure 3, contact finger 27 and speedometer pointer12 cooperate to form a normallyopen electrical switch in an energizingcircuit for alarm 24. This switch is open until such time as thespeedometer pointer is driven into contact with contact finger 27. Withthis occurrence, current flow from battery 28 through alarm 24, brush23, pulley 18, cable 20, selector pointer 13, and speedometer pointer 12back to battery 28 through ground energizes the alarm thereby renderinga signal indicative of speed equal to or in excess of the selectedspeed.

An alternative arrangement for supporting pulley 18 and for establishingan electrical connection therethrough to cable 20 is shown in Figure 6.In this instance pulley 20 is rotatably supported on a fixed shaft 30which is formed with a head 31. Electrical connection from alarm 24 topulley 18 is established through stop plate 32 which is fixed to theleft end of head 31. Shaft 30 is insulated from metallic housing 15 bymeans of Washers 34, 35 and 36 and sleeve 37 which are fabricated byinsulating material, thereby preventing an unwanted shorting of pulley18 to housing 15.

In order to avoid excessive sparking, in certain installations it may bedesirable to energize alarm 24 from a relatively low voltage source. Inthese instances it is desirable to employ a voltage reducer such as adivider to apply less than the total battery voltage to the circuitry.In the event an alternating-current energizing source is to be employedin lieu of a battery, a step-down transformer can be used to energizethe alarm.

It is to be understood that the above-described arrangement isillustrative of the application of the principles of this invention.Numerous other arrangements may be devised by those skilled in the artwithout departing from the scope of this invention.

Having thus described the invention, what is claimed as new and desiredto be secured by Letters Patent is:

1. In a speedometer including a pivoted speedometer pointer movable overa speed indicator dial and housed within a protective casing including atransparent plate rendering at least a portion of said dial and pointervisible, the improvement for actuating a speed indicator alarmcomprising a pair of pulleys supported by said casing immediately belowsaid transparent plate, a cable carried by said pulleys and forming aclosed loop, a triangular speed selector pointer fixedly coupled to oneleg of said cable and loosely coupled to the other leg of said cable,said selector pointer overlying at least in part the portion of saiddial which is exposed, a linear speed selector scale formed upon saiddial and graduating the path of movement of said selector pointer intospeed readings, a contact finger fixedly coupled to said selectorpointer and projecting rearwardly into the path of said speedometerpointer whereby a closed electrical circuit for actuating said alarm maybe established, and a knob positioned in front of said speedometer andcoupled to said cable whereby said selector pointer may be manuallypositioned at a selected speed at which the alarm is to be actuated.

. 2. In a speedometer including a pivoted speedometer pointer movableover a speed indicator dial and housed within a protective casingincluding a transparent plate rendering at least a portion of said dialand pointer visible, the improvement for actuating a speed indicatoralarm comprising a pair of pulleys supported by said casing immediatelybelow said transparent plate, a cable carried by said pulleys, a speedselector pointer coupled to said cable and linearly movable therewith,said selector pointer overlying at least in part of the portion of saiddial which is exposed, a linear speed selector scale formed upon saiddial and graduating the path of movement of said selector pointer intocalibrated speed readings, a contact finger fixedly coupled to saidselector pointer and projecting rearwardly into the path of saidspeedometer pointer whereby a closed electrical circuit for actuatingsaid alarm may be established, and a knob positioned in front of saidspeedometer and coupled to said cable whereby said selector pointer maybe manually positioned at a selected speed at which the alarm is to beactuated.

3. In a speedometer including a pivoted speedometer pointer movable overa speed indicator dial and housed within a protective casing including atransparent plate rendering at least a portion of said dial and pointervisible, the improvement for actuating a speed indicator alarmcomprising a pair of pulleys supported by said casing, a cable carriedby said pulleys, a speed selector pointer coupled to said cable andlinearly movable therewith, said selector pointer overlying at least inpart a portion of said dial, a linear speed selector scale formed uponsaid dial and graduating the path of movement of said selector pointerinto speed readings, a contact finger fixedly coupled to said selectorpointer and projecting into the path of said speedometer pointer wherebya closed electrical circuit for actuating said alarm may be established,and a knob positioned in front of said speedometer and coupled to saidcable whereby said selector pointer may be manually positioned at aselected speed at which the alarm is to be actuated.

4. In a speedometer including a speedometer pointer movable over a speedindicator dial, the improvement for actuating a speed indicator alarmcomprising a plurality of spaced pulleys, a taut cable carried by saidpulleys, a speed selector pointer coupled to said cable and linearlymovable therewith, said selector pointer overlying at least in part aportion of said speed indicator dial, a linear speed selector scaleformed upon said dial and graduating the path of movement of saidselector pointer into speed readings, a contact carried by said selectorpointer and projecting into the path of said speedometer pointer wherebya closed electrical circuit for actuating said alarm may be established,and a knob positioned in front of said speedometer and coupled to saidcable whereby said selector pointer may be manually positioned at aselected speed at which the alarm is to be actuated.

5. In an indicator including a pivoted pointer movable over an indicatordial and housed within a protective casing including a transparent platerendering at least a portion of said dial and pointer visible, theimprovement for actuating an indicator alarm comprising a pair ofpulleys supported by said casing immediately below said transparentplate, a cable carried by said pulleys, selector pointer coupled to saidcable and linearly movable therewith, said selector pointer overlying atleast in part the portion of said dial which is exposed, a linearselector scale formed upon said dial and graduating the path of movementof said selector pointer, a contact finger fixedly coupled to saidselector pointer and projecting rearwardly into the path of said pivotedpointer whereby a closed electrical circuit for actuating said alarm maybe established, and a knob positioned in front of said indicator andcoupled to said cable whereby said selector pointer may be manuallypositioned at a selected value at which the alarm is to be actuated.

6. In an indicator including a pointer movable over a graduatedindicator dial, the improvement for actuating an indicator alarmcomprising a plurality of spaced pulleys, a cable carried by saidpulleys, a selector pointer coupled to said cable and linearly movabletherewith, said selector pointer overlying at least in part a portion ofsaid dial, a linear selector scale graduating the path of movement ofsaid selector pointer, a contact carried by said selector pointer andprojecting into the path of said first pointer whereby a closedelectrical circuit for actuating said alarm may be established, and aknob coupled to said cable whereby said selector pointer may be manuallypositioned at a selected value at which the alarm is to be actuated.

7. In an indicator including a pointer movable over a graduatedindicator dial, the improvement for actuating an indicator alarmcomprising a plurality of spaced pulleys, a cable formed into a closedloop carried by said pulleys, selector pointer coupled to said cable andlinearly movable therewith, a linear selector scale graduating thelinear path of movement of said selector pointer, a contact carried bysaid selector pointer and projecting into the path of said first pointerwhereby a closed electrical circuit for actuating said alarm may beestablished, and means driving said cable upon the supporting pulleyswhereby said selector pointer may be manually positioned at a selectedindicator value at which the alarm is to be actuated,

8. In an indicator including a pointer movable over a graduatedindicator dial, the improvement for actuating an indicator alarmcomprising a plurality of spaced supporting means, a cable formed into ataut closed loop having two relatively linear leg portions and carriedby said means, a selector pointer coupled to said cable and linearlymovable therewith, a linear selector scale graduating the linear path ofmovement of said selector pointer, a contact carried by said selectorpointer and projecting into the path of said first pointer whereby aclosed electrical circuit for actuating said alarm may be established,and means driving said cable relative said supporting means whereby saidselector pointer may be manually positioned at a selected indicatorvalue at which the alarm is to be actuated.

References Cited in the tile of this patent UNITED STATES PATENTS2,163,111 Striemer et al. June 20, 1939 2,169,268 McCullough Aug. 15,1939 2,419,394 Erhard Apr. 22, 1947 2,484,038 Kirlin Oct. 11, 19492,728,072 Magid Dec. 20, 1955

